The invention generally relates to high speed weighing equipment of the type employing a conveyor to transport containers one at a time across a vertically deflectable weigh pan or scale device operable to effect weighing of the products. More particularly, the invention relates to improvements in weighing equipment of the type intended for use in the weighing of containers having either circular or oval footprint configurations and employing conveyors characterized as having a pair of parallel conveying elements, such as endless chains, arranged to underengage the footprints of the containers as they transport the containers for movement across a weigh pan.
In commonly assigned U.S. patent application Ser. No. 07/942,647, filed Sep. 9, 1992, there is disclosed a method and apparatus for weighing products of either circular or oval footprint configuration, wherein the products are supported by conveyor chains arranged to underengage the footprints only immediately adjacent the periphery thereof in order to minimize the effective length of products, as seen by the weigh pan. In a preferred embodiment, the length of the weigh pan in the direction of product movement is chosen to correspond essentially to a dimension of the product to be weighed, as measured in the direction of conveyor movement.
Once a given checkweigher has been fitted with a weigh pan of a given length to effect weighing of product of a given dimension, the checkweigher may not thereafter be used efficiently in the weighing of products having substantially different dimensions, without first affecting a substantial reconstruction of the checkweigher, including the mounting of a new appropriately sized weigh pan.